Gas supply street st. Osipenko, Baymak - diploma

Contents

Assignment No. 05 for the course project

Technical Design List (TP)

1 Introduction

2 Characteristics of the construction area

3 Calculation of gas fuel characteristics

3.1 Composition and properties of natural gas

3.2 Calculation of natural gas characteristics

3.2.1 Calculation of combustion heat

3.2.2 Calculation of gas fuel density

3.2.3 Calculation of gas density relative to density

air

3.2.4 Calculation of air volume required for combustion

3.2.5 Determination of combustion products volumes

4 Selection of gas distribution systems route

5 Determination of estimated gas flow rates

5.1 Determination of number of consumers

5.2 Gas flow rate determination

6 Basic Provisions for Calculation of Low Pressure Networks

7 Hydraulic in-house gas pipeline

8 Selection of gas control station equipment 30 8.1 Installation of gas control stations

8.2 Selection of gas control station

9 Safe operation of gas control systems

and equipment

1 introduction

1.1 This diploma project on the topic "Gas supply of the street st. Osipenko Baymak" was completed on the basis of task No. 26 and regulatory documents:

- SNiP 42012002 "Gas distribution systems";

- PB 12.52903 "Safety rules for gas distribution and gas consumption systems."

1.2 Osipenk Street of Baymak is gasified in this diploma project. The source of gas supply of this microdistrict is a medium-pressure gas pipeline.

In the diploma design, the hydraulic calculation of the low pressure gas pipeline is carried out, the volumes of construction and installation work are calculated, a local estimate is made for the laying of the low pressure gas pipeline.

Osipenko Street is built up with one-story houses. 62 houses are gasified. The gas pipeline is laid along street passes by underground method at a depth of 0.8 m. The gas pipeline is designed from steel electric welded pipes as per GOST 10.70491. The pipeline is designed to be protected from corrosion by three-layer insulation of polymer belts of the type "very enhanced protection" and cathode stations according to GOST 9.6022005.

1.3 Gas economy is a complex technological complex of gas distribution and gas consumption systems, designed to provide consumers with natural and liquefied hydrocarbon gases and use these gases as fuel.

Natural gas is a highly efficient energy carrier, gas supply is a single isoformenergy supply, which is an activity to provide gas to consumers through gas distribution and gas supply systems.

Gasification - odnaizosnovsotsialnoekonomicheskogorazvita, an obespechivayushchayauluchsheniyeusloviytrudaibytaye, an environment atakzheumensheniyezagryazneniye. Therefore, the technical operation of gas supply systems determines the overall efficiency of gasification.

Objects of gas distribution and gas consumption systems belong to hazardous production facilities, and the organizations operating them are obliged to comply with the provisions of the Federal Law "On Industrial Safety of Hazardous Production Facilities" dated 21.10.97 No. 116FZ, other federal laws, other regulatory legal acts and regulatory and technical documents in the field of industrial safety, and perform a set of maintenance and repair measures ensuring the maintenance of hazardous production facilities, gas distribution and gas consumption systems in a serviceable and safe state.

Safe operation of gas supply equipment and systems is regulated by the following main documents: construction codes and rules "Gas distribution systems"

- SNiP 42.012002, set of rules "Basic provisions for the design and construction of gas distribution systems made of metal and polyethylene pipes"

- SP 42.1012003, "Safety Rules for Gas Distribution and Gas Consumption Systems"

- PB 12.52903, "Safety Regulations for Facilities Using Liquefied Hydrocarbon Gases"

- PB 12.60903, as well as a number of other regulatory legal acts and documents, in particular, industry standards for technical operation of gas distribution systems

- GOST 15339.3-051-2003,

- GOST 15339.3-052-2003

- GOST 15339.3-053-2003, developed by

- OJSC "HyproNIIgas" and approved by the Ministry of Energy of the Russian Federation.

The specified industry standards, in addition to the requirements for the operation of equipment and gas supply systems, give a detailed technology for the technical operation of gas distribution systems.

To ensure safe operation of gas supply systems, special agencies, services, sections and other kind of subdivisions are created that organize and perform technical operation of gas distribution systems facilities in accordance with the requirements of the above regulatory and technical documents.

2 characteristics of the construction area

The projected area of ​ ​ laying the low-pressure gas pipeline route is located in the western part of the Republic of Bashkortostan.

The climate of the region is temperate, characterized by cold winters and short heat in summer. Transitions from winter to summer and from summer to winter are short.

Meteorological characteristics of the construction area:

- average maximum outside air temperature of the hottest month is + 26.60С;

- the average minimum air temperature of the coldest month is - 160С;

- wind speed, the probability of which is 5%, 11 m/s;

- design air temperature at absolute maximum + 420С and absolute minimum - 440С.

On the territory of the construction district, sandy soils prevail. Soup - a mixture of sand (up to 40%) with clay (30%) and carbon dioxide, with calcium salts and iron hydroxides. Soup is grade II soil .

Design depth of freezing of soils of the sandy concrete construction area 172cm. The normative freezing depth is taken equal to the average of the annual maximum depths of seasonal freezing of the soil according to the observation of the actual freezing of the soil.

The minimum depth of gas pipelines should be taken to be 0.8 m. In this case minimum depth of gas pipeline laying is accepted equal to 0.9 m. Guards Street in Baymak is built up with one-story houses. The total number of houses is 60. There are no utilities and industrial enterprises on the street. Residential buildings use gas for heating and cooking. Residential buildings are heated by capacitive water heaters of AOGV type with a gas flow rate of 2.125 m3/h. For cooking, four-block slabs of SG 4 with a gas flow rate of 1.25 m3/h are used.

Residential buildings are supplied with gas from lower pressure gas pipelines through the FRG, which reduces the pressure from 0.3MPa to 0.003MPa.

When laying an underground gas pipeline, all normative distances from the gas pipeline to communications and structures are observed according to SNiP 42.01-2002:

- to the foundations of buildings - not less than 2 m;

- to the edge of roads - not less than 1.5 m;

- to water supply, sewerage, heating system - not less than 1 m.

Roads in the construction area have asphalt pavement, intersections with roads are made in cases with installation of control tubes. Local roads belong to category V.

3 route selection and installation of gas supply systems

3.1 The gas supply system must be reliable and economical, which is determined by the correct choice of the gas pipeline route, which depends on the distance to consumers, the width of the driveways, the types of pavement, the presence of various structures and obstacles along the route, as well as the terrain.

The minimum depth of gas pipelines should be at least 0.8 m. In places where no traffic is provided, the depth of the gas pipeline can be 0.6 m. At the underground intersection of the motorways, gas pipelines are laid in special cases, and the ends of the cases for tightness are sealed with a ground linen strand with bitumen.

In these places, gas pipelines of the common network are laid to a depth of 2.0 m during open work, and 2.5 m during work by puncturing. The distance is taken from the sole of the rail to the top of the case.

The gas pipeline shall have disconnecting devices installed at a distance of not more than 1000 m from the intersection.

In this case, if the gas pipeline is annular, then the disconnecting devices are placed on both sides, if the dead ends are on the side of the gas inlet. The gas pipelines inside the case shall have a minimum number of welded joints, which shall be checked by physical inspection. Section of gas pipeline is covered with very reinforced insulation and laid on centering dielectric gaskets.

At the end of the case, a control tube is installed, with its help it is possible to detect the presence of gas in the case. Lower part of tube is welded to case, fine gravel or layer of crushed stone is filled into space between case and gas pipeline. End of tube is brought under carpet and closed with plug.

Above-ground crossings are made through water barriers, with an unstable channel and banks, with high water flow rates, as well as through deep ravines.

In urban conditions, transitions through water barriers, as a rule, make underwater two-stranded. At the same time, each line must provide 75% of the calculated gas flow rate. The place of the river crossing device is selected on a rectilinear section with a calm current, with a stable channel and non-washable gentle banks.

Gas pipeline routing. The gas pipeline is routed along street driveways, observing the requirements of the SNiPa and the rules of operation. Gas pipeline is laid underground

. Gas pipeline routes are selected taking into account gas transportation in shortest way.

With gas leaks from underground gas pipelines, serious accidents can occur due to gas accumulation in various places, sometimes even at a significant distance from the site of damage to the gas pipeline. Gas, reaching the basements, wells and channels of other underground communications, accumulates in them and creates explosive concentrations. The most dangerous in this regard are the basements of buildings, telephone and heating tunnels, since they are directly connected with housing and public buildings. Gas can also spread over a considerable distance when entering sewage pipes, although they are usually located deeper than gas pipelines

Various obstacles affect the routing of gas pipelines: rivers, reservoirs, ravines, highways, etc.

For settlements with the old layout, when the quarters have a continuous development along the perimeter and consist of separate buildings, gas pipelines are laid along each passage and street.

Crossing each other, they form a ring. From street gas pipelines, inlets are laid into each building. In urban areas with a new layout, gas pipelines are located inside the quarters.

When routing gas pipelines, it is necessary to observe the distance from the gas pipeline to other structures. For example, the vertical distance between gas pipelines and such structures as water supply, heat network, sewerage, drains, at their mutual intersection should be at least 0.2 m, and between the gas pipeline and electric cable, telephone cable - at least 0.5 m.

It is allowed to reduce the distance between the gas pipeline and the electric cable or communication cable when laying them in the case. The distance between the gas pipeline and the wall of the case when laying an electric cable must be at least 0.25 m, the communication cable - at least 0.15 m. The ends of the case must go 2 m to both sides of the walls of the crossed gas pipeline.

It is allowed to lay two or more gas pipelines in one trench at one or different levels. At the same time, the distance between gas pipelines in the light should be provided sufficient for their installation and repair of pipelines.

In cities and settlements located in mountainous and hilly areas, when choosing the location of the GRP, it is necessary to take into account additional hydrostatic pressure.

Depth of gas pipeline laying depends on composition of transported gas, soil-climatic conditions, value of dynamic loads. Gas pipelines transporting dried gas can run in the zone of ground freezing. The minimum depth of the gas pipeline shall be 0.8 m to the top of the gas pipeline or case. In places where no traffic is provided, the depth of gas pipelines can be reduced to 0.6 m.

Laying of gas pipelines transporting non-drained gas shall be provided below the zone of seasonal ground freezing with a slope to condensate collectors of at least 2%.

Soil and road cover protect gas pipelines from mechanical damage and serve as heat insulation against sharp temperature fluctuations.

Dynamic loads arising in gas pipelines due to heavy traffic of vehicles should not create dangerous stresses in pipes. Stresses arising in the ground from moving vehicles are dispersed at a depth of 0.7 m with improved coatings and 0.750.8 m with cobbled coating.

When laying a gas pipeline in the zone of freezing of soils, it is necessary to take into account the properties of soils. Their negative properties are beam, they are possessed by soils, which, when frozen due to loosening with ice crystals, increase in volume. As a result of swelling, the soil raises the gas pipeline, which, having tested high stresses, can deform and break in the butt joints.

The advantages of underground laying of gas pipelines are the creation of a relatively constant temperature regime. Stresses arising in gas pipelines due to temperature change are directly dependent on the temperatures of the pipe body. Voltage values can be increased in open sections of gas pipelines. It is clear how important it is to reduce the temperature changes of gas pipelines due to the correct selection of their depth.

When laying the gas pipeline in the ground, it should be:

- install compensating devices on the gas pipeline for perception and reduction of voltages;

- when laying gas pipelines in zones with increased dynamic loads, increase the depth of the gasket and lay gas pipelines in special protective devices;

- perform welding works on gas pipelines in the coldest time of the day in summer and the warmest time in winter;

- city gas pipelines transporting wet gas, lay below the zone of ground freezing with a slope that ensures the flow of formed moisture into special tanks - condensate collectors.

Inlets of non-dried gas pipelines into buildings and structures shall be provided with a slope towards the distribution gas pipeline. If the necessary slope to the distribution gas pipeline cannot be created according to the terrain conditions, it is allowed to provide for the laying of a gas pipeline with a fracture in the profile and the installation of a condensate collector at the lowest point.

The laying of gas pipelines in soils with the inclusion of construction debris and distillation should be provided with a device for the gas pipeline of a base of soft or sandy soil with a thickness of at least 10 cm.

Filling of the gas pipeline should be provided with the same soil to the full depth of the trench. In the presence of groundwater, measures should be envisaged to prevent the surfacing of gas pipelines, if this is confirmed by the calculation.

Of great importance is the qualitative state of the bottom of the trench.

A reliable bed is sand, therefore, when laying gas pipelines in rocky or frozen soils, a sandy pillow 20 cm high is made. The bed is made so that during operation there are no drawdowns that can lead to gas pipeline sagging. Sagging is dangerous, since during bends in pipes there are high stresses, which are the reason for rupture of joints of welded joints.