Electrical equipment and power supply of pump station No. 1 of Energoservis LLC in Yuryuzan

Contents

Contents

Introduction

1 Information on the pump station

1.1 Purpose of pump station electrical equipment

1.2 Technical characteristics of pump station electrical equipment

1.3 Characteristics of pump station power supply

2 Calculation of pump station electrical equipment

2.1 Selection of current type and voltage value of pump station motors

2.2 Selection of type and number of working pumps

2.3 Calculation and selection of pump motor power

2.4 Category of reliability of power supply and selection of power supply scheme of the enterprise

2.5 Pump station control diagram

2.6 Calculation and selection of control devices, pump station protection

2.7 Pump station automation and protection system

2.8 Calculation of pump station lighting

3 Calculation of cost of wiring replacement for lighting

3.1 Feasibility study of costs of electrical equipment and materials

3.2 Calculation of the wage fund, social insurance and social security contributions

3.3 Other Cost Calculation

3.4 Calculation of cost estimates for electrical installation work

4 Occupational safety and fire safety

4.1 Pump Maintenance Safety

4.2 Main requirements of pump station fire safety

4.3 Possible pump faults and methods of their elimination

Conclusion

List of sources used

Introduction

Transmission, distribution and consumption of electricity in industrial enterprises should be carried out with high economy and reliability. So, in shop power supply systems, switchgears (KRU) and complete transformer substations (KTP), as well as complete power and lighting current wires, are widely used.

All this creates a flexible and reliable power distribution system that saves a large number of wires and cables. The schemes of substations of various voltages and assignments were significantly simplified due to the rejection of prefabricated buses and switches at primary voltage and the use of blind connection of substation transformers to supply lines, etc.

The main determining factors in the design of power supply should be the characteristics of power supply sources and electricity consumers, primarily the requirement for uninterrupted power supply, taking into account the possibility of providing redundancy in the process part of the project, the requirements of electrical safety.

Connection of power supply systems of industrial enterprises to the networks of power systems is carried out in accordance with the specifications for connection issued by the power supply organization in accordance with the Rules for the use of electric energy.

When designing power supply systems, it should be borne in mind that at present, an input is becoming increasingly widespread, which allows us to bring the highest voltage (35-330 kV) as much as possible closer to the electric devices of consumers with a minimum number of intermediate transformation stages. The fundamental principle in the design of power supply schemes is also the rejection of the "cold" reserve. Rational solution circuits shall ensure limitation of short circuit currents. If necessary, reactive power compensation shall be provided during design of power supply systems. Measures to ensure the quality of electricity should be decided comprehensively and based on rational technology and production regime, as well as on economic criteria. At equipment selection it is necessary to seek for unification and to be guided by use of complex devices (CREWE, CSR, etc.) various tension, capacities and appointments that increases quality of electroinstallation, reliability, convenience and safety of its service.

Power supply schemes of industrial enterprises shall be developed taking into account the following basic principles:

power supply sources shall be as close as possible to electric power consumers;

the number of power conversion and distribution stages at each voltage should be as small as possible;

distribution of electricity is recommended to be carried out according to main circuits and in justified cases radial circuits can be used;

power supply and electrical connection diagrams of substations shall be made in such a way that the required level of reliability and redundancy is provided with a minimum number of electrical equipment and conductors.

The purpose of this project is power supply and electrical equipment of the pump station. To achieve this goal, the following tasks must be performed:

selection of current type and voltage value of pump station motors;

selection of type and number of working pumps;

calculation and selection of pump motor power;

category of reliability of power supply and selection of power supply scheme of the enterprise;

calculation and selection of control devices, protection of the pump station;

calculation of pump station lighting;

Feasibility study of costs of electrical equipment and materials;

calculation of the wage fund, social insurance and social security contributions;

Calculation of other costs

calculation of cost estimates for electrical installation work.

Information on pump stations

Purpose of pump station electrical equipment

Electrical equipment at the pump station is designed to improve the operability of personnel.

The number of auxiliary pumps depends on the number of main pumps of the station, their power, the volume of the building and other conditions. In addition to the main ones, backup pumps of the same purpose are provided.

The main motors of the electric drives of the pumps are asynchronous short-circuited. As a rule, they operate at a voltage of 380 volts. This voltage is sufficient, since the power of the motors and the distance between their installation place and the auxiliary transformer are small. Some engines (internal combustion engines) of DVS are used only on standby pumps during the isolated work of the station when great demands are placed on their reliability.

Motors and pumps are supplied complete. Thus, the conformity of engine and pump parameters is ensured by the supplier.

The electric drive for gate valves (electric or solenoid) is most common, it allows remote or automatic control of them. When determining the load it creates, it is necessary to proceed from the simultaneously consumed power, which depends on the technological mode of operation of the station.

The lighting of the pump station, as well as the usual premises, is carried out using lighting fixtures with filament lamps at a voltage of 220 V. The lighting quality should ensure the possibility of correct and safe maintenance of the units. Portable lighting is allowed only at a voltage of 12 V. For outdoor lighting, lamps with filament lamps, high-pressure mercury lamps or spotlights are used. The power required for internal lighting shall be 8-10 W/m2 and 0.12 W/m2 for external lighting.

Ventilation of the pump station is designed to create normal operating conditions for the pump station and the safety of its equipment. The respective temperature and humidity shall be maintained in its premises. The temperature difference between internal and external air in the machine hall of the station with constantly present personnel should not exceed 5 wasps, and at the automated stations which are periodically serviced by personnel - 10 wasps. On the recommendation of Hydrovodkhoz, when cooling the air in the engine room of the station, the average temperature of the hottest month in the area of ​ ​ the station construction is measured at 13 hours. The heat sources at the pump station are operating motors, current-carrying parts (wires, buses, cables), heated walls of the building, etc. The sources of additional heat are electric heating heaters.

Calculation of pump station electrical equipment

Selection of current type and voltage value of pump station motors

For power electric networks of industrial enterprises, three-phase alternating current is mainly used. It is recommended to use direct current in cases where it is necessary according to the process conditions (charging of batteries, power supply of galvanic baths and magnetic tables), as well as for smooth control of the speed of electric motors. If the need for the use of direct current is not caused by technical and economic calculations, then three-phase alternating current is used to supply power equipment.

When choosing a voltage, take into account the power, number and location of electric receivers, the possibility of their joint power supply, as well as technological features of production.

When selecting voltage for power supply directly to electric receivers, it is necessary to pay attention to the following provisions [9]:

Nominal voltages used in industrial enterprises for power distribution are 10-6 kW; 660, 380, 220 V.

It is recommended to use a voltage above one kilovolt at the lower stage of power distribution only if special electrical equipment is installed that operates at a voltage above one kilovolt.

If the motors of the necessary power are manufactured at several voltages, then the issue of choosing the voltage must be resolved by a technical and economic comparison of the options.

In case the application of voltage above one kilovolt is not caused by technical necessity, the use of voltage of three hundred eighty and six hundred sixty volts should be considered. The use of lower voltages to power power consumers is not economically justified.

When choosing one of the recommended voltages, it is necessary to proceed from the condition of the possibility of joint power supply to power and lighting electric receivers from common transformers.

Using a voltage of six hundred and sixty volts, power losses and consumption of non-ferrous metals are reduced, the range of shop substations increases, the unit power of the used transformers increases, and as a result, the number of substations is reduced, and the power supply scheme at the highest stage of energy distribution is simplified. The disadvantages of a voltage of six hundred and sixty volts are the impossibility of joint power supply to the lighting network of power electric receivers from common transformers, as well as the absence of low-power motors for this voltage, since at present such motors are not produced by our industry.

At enterprises with a predominance of low-power electric receivers, it is more profitable to use a voltage of three hundred eighty or two hundred twenty volts (unless the feasibility of using another voltage is proved).

The voltage of DC networks is determined by the voltage of the supplied electric receivers, the power of the converter units, their distance from the center of electrical loads, as well as environmental conditions.

Select 380 volts for pump station motors.

Pump station control diagram

The diagram provides two modes of engine control:

1) remote - from the control room (SB3 SB4 control buttons);

2) local - by means of control buttons located directly at the pump unit (SB1, SB2).

The engine is started by pressing SB1 button (SB3), at that the pump must be filled with water (contact of SL filling control relay will be closed). When the SB1 button (SB3) is pressed, the intermediate relay coil KL1 and the magnetic starter coil KMZ are powered. One of the contacts KL1 shunts the button SB1 (SB3), and the other supplies power to the coil of the intermediate relay KL4. The KMZ contact supplies the signal to the solenoid of YAC1 actuation of oil switch Q1. When switch Q1 is switched on, the engine stator is connected to the mains through the LR reactor. When it is connected to the network at the initial moment of start (asynchronous start), a current passes in the stator circuit several times higher than the nominal one, as a result of which the current relay KA connected to the current transformer connected to the stator of the motor M. The contact of this relay turns on the time relay KT2. In the coil circuit of the intermediate relay KL5, the contact KT2 opens and prepares the circuit for switching on the contactor KM2 and the magnetic starter KM4, which are connected through the contacts KL5 of the intermediate relay. As the engine accelerates, the current in the stator subsides and at a sub-synchronous speed (0.95-0.98 synchronous) it decreases significantly, while the spacecraft relay opens its closing contact in the KT2 circuit. With a time delay (about 0.9 s), the contact of the relay KT2 in the circuit of the coil KL5 will close. The contactor KM2 turns on and connects a direct current to the excitation winding M, and at the same time, through the closing contact KM4 (the starter KM4 turns on simultaneously with the contactor KM2), the electromagnet YAC2 of the oil switch Q2 is powered on. The LR reactor is shunted by the switch Q2 and the full mains voltage is applied to the stator of the engine, the engine is synchronized. When KM2 is switched on, the circuit of the discharge resistor Rp opens.

In order to facilitate the entry of M into synchronism, if the voltage of the supply network is reduced, an excitation forcing unit is provided in the control circuit.

Forcing can be performed in two ways:

by means of voltage relay KV3 connected to secondary winding of voltage transformer used in control circuit of this motor (individual forcing);

by means of voltage relay KV4 connected to group forcing buses on switchgear (group forcing).

In case of individual forcing of relay KV3 with opening contact (if mains voltage is reduced), it turns on contactor KM1, which shunts resistor of excitation regulator Rb with its contact, which provides forced excitation of synchronous motor M.

The disadvantage of individual forcing is the possibility of false forcing in the event of the automatic disconnection of circuits leaving the voltage transformer connected to the switchgear.

More reliable is the so-called group forcing, in which the contactor KM1 is turned on by the closing contact of the relay KV4. In turn, it is turned on when power is supplied to the group forcing buses, when the voltage of the high-voltage network decreases by 1520%. In this case, by directly connecting the relay to the terminals of the secondary winding of the voltage transformer, the possibility of false forcing is excluded.

Method of forcing is selected using contact pads HV1 and HV2.

The synchronous motor is disconnected:

pressing SB2 button (SB4);

relay protection actuation;

if after start-up the pump does not develop the required pressure (contact SP in the circuit breaker disconnection circuit);

at actuation of pump filling control relay.

Calculation and selection of pump station control and protection devices

2.6.1 Selection of pump station control and protection devices

Electric consumers (electric drives, electric heating devices, lighting and installations) are controlled and protected from emergency operation modes by electrical devices called control and protection devices.

To increase the service life of electric consumers, it is necessary to technically correctly choose the necessary control and protection equipment for power cells. Developed schematic electrical control circuit. To choose devices is to select from a large number of the same type of devices the most advanced, cheap device, the technical data of which meet the conditions of choice, safety requirements and fire rules.

Devices are selected by voltage value, type and value of current, climatic versions, conditions of protection against environmental influence, its compliance with technological requirements and other indicators.

When selecting, the nature and mode of operation of electric receivers must also be taken into account.

When selecting control and protection devices, it is advisable to use the structures of the device symbols, choosing from them those that are necessary for the specific use of the device.