Diploma Calculation of Compressor Shop

Contents

              Contents

1. Introduction

2. Analytical Overview

  2.1. Gas transfer units  with gas turbine unit 

  2.2.   Electrically Driven Gas Transfer Units 

Gas transfer units  with gas-motor compressor

installation

3.  Project Development

 Calculations of the main gas pipeline section

       3.1.1. Calculation of gas density

       3.1.2. Thermohydraulic calculation of the designed

                         section of the main gas pipeline

       3.1.3. Pipeline  Strength and Stability Calculation 

Economic justification of the selected option 

          construction of the Constitutional Court

       3.2.1 Initial data

       3.2.2. Define Capital Investments

       3.2.3.  Determination of operating costs

 Determination of specific cost of gas transportation 

  3.3.  Substantiation of GPA selection  of compressor shop

  3.4.  Description of the selected GAP design 

       3.4.1.    Gas turbine drive unit

       3.4.2.    BN supercharger unit

  3.5.  Development of process diagram

       3.5.1.    Gas Purification Unit

       3.5.2.  Site of gas pumping units

3.5.3.    Gas Cooling Unit

  Fuel, start-up preparation unit 

 and pulse gas

3.5.5.  Oil system of compressor station

  3.6. UPTIPG Automatic  Control System 

4.  Health  and Safety 

5.  Environmental protection 

   List of literature

1. Introduction

Currently, an extensive system of gas main pipelines operates on the territory of the Russian Federation and neighboring countries, allowing gas transport in the territories from the northern regions of Western Siberia to the countries of Western Europe and Asia Minor. Such gas pipeline systems no longer exist in the world. Currently, the gas industry continues to work and develop. The development of gas and a number of related industries today largely depends on the further improvement of the operation and maintenance of natural gas pipeline systems from remote and sometimes poorly developed regions to industrial and central areas. Gas is supplied to them through gas pipelines of various diameters.

The optimal mode of operation of the main gas pipelines is, first of all, the maximum use of their capacity at the minimum energy costs for compressing and transporting gas through the gas pipeline. To a large extent, this mode is determined by the operation of compressor stations installed along the gas pipeline route. When the gas passes, there is friction of the flow against the pipe wall, which causes a loss of pressure. Therefore, it is impossible to transport natural gas in sufficient quantities and over long distances only due to natural formation pressure. For this purpose, it is necessary to build compressor stations that are installed on the gas pipeline route every 100150 km. The length of the gas pipeline sections between compressor stations is calculated, on the one hand, based on the value of the gas pressure drop in this section of the route, and on the other, based on the connection of the station to settlements, water supply sources, electricity and the like .

Before supplying gas to the main gas pipelines, it must be prepared for transportation at the head structures, which are located near the gas fields. Gas preparation consists in its removal from mechanical impurities, drying from gas condensate and moisture, as well as removal if they exist, by-products: hydrogen sulfide, carbon dioxide and so on. When formation pressure falls, so-called booster compressor stations are built near gas deposits, where the gas pressure is raised to 5.47.4 MPa before it is supplied to the compressor station of the main gas pipeline.

The optimal operation mode of compressor stations depends to a large extent on the type and number of gas pumping units installed at the station, their energy parameters and process modes of operation.

The main types of gas pumping units at compressor stations are currently:

- units driven by gas turbine units;

- electrically driven units;

- piston gas-engine compressors.

The type of compressor station drive and its capacity are mainly determined by the capacity of the gas pipeline. Gas compressors are used for underground gas storage stations where high compression ratios and low flow rates are required. For high-throughput gas pipelines, centrifugal superchargers driven by gas turbine plants or electric motors find the most effective use.

The features of the gas turbine drive operation to the best extent, among the mentioned types of gas pumping units, meet the requirements for the operation of gas transmission systems: high unit power (from 6 to 25 MW), small relative weight, block-complete design, high level of automation and reliability, autonomy of the drive and its operation on pumped gas. To drive the supercharger, such units use reconstructed ship or aircraft gas turbine engines.

That is why this type of drive has become most widespread in gas pipelines (over 85% of the total power of units installed at compressor stations).

Gas pumping units with a supercharger drive from synchronous motors have become somewhat less widespread. In terms of unit capacity, such units are slightly inferior to a gas-turbine-driven unit - the most common are units with a capacity of 4 MW and 12.5 MW, even several units with a capacity of 25 MW operate. Operating costs for such engines are high due to the high cost of electricity, but electrically driven gas pumping units have positive properties:

- high reliability;

- large motor resource of all components of the unit;

- low dependence on climatic conditions (unlike units with gas turbine drive);

- simplicity of automation and control;

- Environmental cleanliness;

- low fire hazard.

All these advantages allow the electric drive units to retain their place in the gas transportation system.

In this diploma project, a section of the main gas pipeline was developed and, in accordance with the specified capacity, a compressor station was designed. The design of the compressor station consists in the selection of equipment. The selection of gas pumping units is based on a feasibility study and an analytical review of existing modern GPAs. The selection of the remaining equipment consists in the selection of the number of units.

2. Analytical overview.

The main gas fields in Russia are located at a significant distance from large consumers. Gas is supplied to them through gas pipelines. When gas moves through the pipeline, there is a loss of pressure due to different hydraulic resistance along the length of the gas pipeline. The pressure drop causes a decrease in the capacity of the gas pipeline. Simultaneously, the temperature of the transported gas decreases, mainly due to the transfer of heat from the gas through the pipeline wall to the soil and atmosphere.

Compressor stations are installed to maintain a given flow rate of the transported gas by increasing the pressure through certain distances along the gas pipeline route, as noted above.

The pressure drop in the section between the combustion chamber determines the degree of pressure increase in the gas pumping units. The gas pressure in the gas pipeline at the end of the section is equal to the pressure at the inlet of the gas pumping unit, and the pressure at the beginning of the section is equal to the pressure at the outlet of the gas air cooling apparatus.

The modern compressor station (SC) is a complex engineering structure that provides the main technological processes for the preparation and transport of natural gas.

The compressor station is an integral and integral part of the main gas pipeline, providing gas transportation using power equipment installed on the combustion chamber. It serves as a control element in the complex of structures included in the main gas pipeline. It is the parameters of the CC operation that determine the mode of operation of the gas pipeline.

The main equipment of the combustion chamber includes:

process gas purification unit (dust collectors and separator filters);

process gas cooling unit;

gas transfer units;

compressor station process piping;

isolation valves of process pipelines of units binding;

starting, fuel and pulse gas preparation unit;

auxiliary equipment (oil, boiler room, air compressor, etc.);

power equipment (transformer, substation, switchgear, etc.);

main control board and telemechanics system;

equipment for electrochemical protection of CS piping.

On the main gas pipelines, three main types of combustion chamber are distinguished: head compressor stations, line compressor stations and booster compressor stations.

Head compressor stations are installed directly downstream of the gas field. As gas is produced, the pressure in the field drops to a level where it is no longer possible to transport it in the required amount without compression. Therefore, head compressor stations are built to maintain the required pressure and flow. The purpose of the head compressor station is to create the necessary pressure of the process gas for its further transportation through the main gas pipelines. The principal difference between the head compressor station and the line stations is the high compression ratio at the station, provided by the sequential operation of several gas pumping units with centrifugal superchargers or piston gas compressors. At the head compressor stations there are increased requirements for the quality of process gas preparation.

Linear compressor stations are installed on gas main lines, as a rule, after 100150 km. The purpose of the CS is to compensate the natural gas supplied to the station from the inlet pressure to the outlet pressure due to design data. This ensures constant predetermined gas flow through the main gas line. In Russia, linear gas pipelines are being built mainly at a pressure of 5.4 MPa and 7.4 MPa.

Booster compressor stations (DCS) are installed in underground gas storages. The purpose of the DCS is to supply gas to the underground gas storage from the main gas pipeline and remove natural gas from the underground storage (usually in the winter) for its subsequent supply to the main gas pipeline or directly to gas consumers. DCS is also built in a gas field with a drop in formation pressure, below the pressure in the main pipeline. A distinctive feature of DCS from linear combustion chamber is high compression ratio 24, improved preparation of process gas supplied from underground storage in order to clean it from mechanical impurities and moisture carried out with gas.

Gas turbine plants, electric motors and gas-engine compressors are used as the power drive of combustion chamber - a combined unit in which the piston compressor is driven from the crankshaft of the internal combustion engine. The type of compressor station drive and its capacity are mainly determined by the capacity of the gas pipeline. With the increase in the capacity of gas pipelines due to the increase in the diameter of the pipe and the working pressure, the temperature of the gas flowing through the gas pipeline increases. To increase the efficiency of the gas pipeline and primarily to reduce the capacity for gas transportation, it is necessary to install gas air cooling devices at the outlet of each combustion chamber. Temperature reduction is also necessary to maintain insulation of the pipe. An important factor in reducing energy costs for gas transportation is the timely and effective cleaning of the internal cavity of the pipeline from various types of pollution. The internal state of the pipeline has a rather strong effect on the change in energy costs associated with overcoming the forces of hydraulic resistance in the internal cavity of the pipeline. The creation of high-efficiency cleaning devices with a large motor resource allows you to stably maintain the productivity of the gas pipeline at the design level, reduce energy costs for gas transportation by about 1015%.

It is always advantageous to maintain the maximum gas pressure in the pipeline, reduce the temperature of the pumped gas due to cooling at the stations, use large-diameter gas pipelines and periodically clean the internal cavity of the pipeline to reduce the costs of the CS capacity for gas pumping, increase the throughput capacity of the gas pipeline and save energy resources for gas pumping.

When designing a compressor station, the most important issue is the choice of GPA.

Gas transfer units used for gas compression at compressor stations are divided into:

By drive type:

- gas turbine units (GTU),

- motor-operated units (EGAP),

- gas-engine compressor units (MMC).

In terms of capacity and performance:

- N = 4 MW, Q = 7 to 8 mm3/day,

- N = 6 MW, Q = 10.5 to 11 mm3/day,

- N = 12.5 MW, Q = 20 to 21 mm3/day,

- N = 16 MW, Q = 30 to 33 mm3/day,

- N = 25 MW, Q = 45 to 48 mm3/day.

By design:

- with full or incomplete superchargers,

- with oil lubrication of rotor bearings or magnetic suspension,

- with oil sealing system or with "dry" gas-dynamic seals.

Description of the selected GAP design

The 16 MW gas transfer unit of the Volga GPA16 type is designed for the transportation of natural gas through main pipelines, as well as for operation at booster compressor stations and compressor stations of underground gas storage (Fig.3.3). The power drive of the compressor is a power unit based on a drive gas turbine plant of the type UPG16 UKhL1 with an aircraft gas turbine engine NK38 ST. The gas turbine drive unit is designed to accommodate a supercharger drive, drive operability and control systems, and environmental protection systems.

Installation symbol:

UPG-16 gas turbine drive unit

UPG - gas turbine drive unit;

16 - capacity in MW.

Development of process diagram

The process diagram of the compressor station provides for the following main technological processes:

- cleaning of gas from mechanical impurities and liquid to requirements determined by specifications for gas pumping units (GPA) before compression;

- gas compression to the required pressure;

- gas cooling after compression.

To ensure stable operation of the main process equipment, auxiliary systems and installations are provided that ensure the normal operation of the compressor station:

- fuel and pulse gas treatment unit;

- lubrication oil supply, storage and regeneration system.

The process diagram with the list of used process equipment is presented in the drawing DPNGTU101200 (99-ICE) 05, l.2.

The technical solutions adopted in the working drawings comply with the requirements of environmental, sanitary, fire and other standards applicable in the territory of the Russian Federation, and ensure safe operation of the facility for life and health of people, subject to the measures provided for in the working documentation.