Course Project for the Design of Compressor Stations and Main Gas Pipelines Technological Calculation of Main Gas Pipelines

Contents

Input Data for Process Calculation of Main Gas Pipeline

1. Introduction

2. Determination of gas pipeline capacity

3. Determination of GPA type, number and operation diagram

4. Determination of gas pipeline diameter

5. Determination of pipe wall thickness

6. Calculation of gas parameters

7. Determination of gas flow regime

8. Determination of distance between CC

9.Define Estimated Cost of Gas Transfer

9.1.Opting for optimal pipeline diameter

9.2.Orientated cost of gas transfer

10. Conclusion

11. Literature

1.vvedeniye

All main gas pipelines on operating pressure are divided into three classes: Ι-high pressure, more than 25 kgfs/cm2, ΙΙ average pressure, from 12 to 25 kgfs/cm2, and ΙΙΙ low pressure up to 12 kgfs/cm2. To increase the throughput capacity taking into account the strength of the pipes, the working pressure is taken as 5055 kgf/cm2, and for newly built ones - up to 75 kgf/cm2. As this pressure decreases during gas movement through the gas pipeline to 3035 kgf/cm2, the initial pressure is restored at combustion chamber.

The route of the main gas pipeline is laid along undeveloped terrain, along the shortest path between the initial and final points and with the smallest intersection of artificial and natural obstacles (rivers, lakes, ravines, railways, motorways, etc.). Depending on the working pressure and diameter, the gas pipeline route for safety purposes should be removed from settlements, industrial enterprises and various structures at a distance of 40 to 250 m. In this exclusion zone, called a security zone, it is not allowed to place permanent or temporary structures, field mills, cattle cattle, warehouses, etc.

Main gas pipelines are mounted from high-quality seamless or electric welded pipes made from low-carbon or low-alloyed steels. Butt-welded pipes are connected without flange connections. The depth of pipe laying, counting from the surface of the pipe to the top of the pipe, should be at least 0.8 m.

Main gas pipelines protect against corrosion with anti-corrosion coatings of a normal, reinforced and very reinforced type, and in especially aggressive soils and areas of wandering currents, electrical methods of corrosion protection are additionally used.

To ensure normal operation of the main gas pipelines, shut-off devices are installed on them, mainly steel cranes of a cold-free plant, blowdown plugs and condensate collection and removal devices.

The combustion chamber is designed to compress the gas to operating pressure in order to provide the design capacity of the main gas pipeline. They are equipped with piston compressors or centrifugal superchargers with a gas turbine or electric drive.

The main facilities of the combustion chamber are gas compression and cooling treatment plants. Auxiliary structures include energy, water, oil, heat supply, ventilation and air conditioning systems. Special attention is paid to automation of the combustion chamber with control of its operation mode from one panel and heat waste disposal.

Centrifugal superchargers for increasing the compression ratio of gas operate sequentially two to three units in a group. The number of groups depends on the capacity of the gas pipeline. The process diagram of the combustion chamber allows the possibility of serial and parallel operation of superchargers and groups, as well as disconnection of any unit without gas flow rupture.

The type of supercharger drive is selected depending on local conditions. In areas remote from powerful power systems, it is advisable to use a gas turbine drive operating on transported gas. In industrial areas with a low cost of electricity, it is more economical to use an electric drive.

The GRS is built at the end of the main gas pipeline or at a branch from it and is designed to supply gas to the gas networks of settlements, industrial enterprises and other large gas consumers. The following are carried out at the GDS: cleaning of gas from mechanical impurities; reduction of pressure to the specified accessory, accounting of gas consumption and, if necessary, its additional odorisation. Depending on the capacity and the value of the inlet and outlet pressure of the gas, there are various GPU process diagrams. Gas reduction can be carried out in one or two stages along two, three or more process lines, of which one is a backup. Modern GRS are automated and are provided with light sound alarm in the locations of maintenance personnel.

Gas pipelines - The branches to the CC and GDS are also part of the main gas pipeline and are fully subject to the requirements and standards for the design and operation of main gas pipelines .

10. conclusion

In this course project, a technological calculation of the main gas pipeline transporting natural gas from the Achakovskoye field was carried out. As a result of the calculation:

1. The capacity of the main gas pipeline, equal to.

2. According to the smallest value of the complex, for complimentation and transportation of natural gas, three CBN 260132 (drive type - GTK5) are adopted, operating in single-stage compression mode, one of which is standby.

3. The average temperature of the transported gas, taking into account the JoulyThomsan effect, is 285.3 K, the flow mode is quadratic.

4. On the section of the main gas pipeline with a length of 1000 km, nine compressor stations were installed, every 111.1 km.

5. Unit costs for the most optimal diameter (82012 mm) are

6. The estimated cost of pumping 1 m3 of gas was.

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