Gas supply to the district of the city and bakery - DP

Contents

Introduction

1. Process Part

1.1 Selection of gas supply system

1.2 Selection of type and quantity of FRG

1.2.1 Gas equipment of FRG

1.3 Protection of gas pipelines against corrosion

1.4 Maintenance and repair of gas pipelines

1.5 Bakery gas supply

1.5.1 Characteristics of the object

1.5.2 Main Design Solutions for Gas Supply

1.5.3 Architectural and construction solutions

1.5.4 Ventilation and heating

1.5.5 Smoke removal

1.5.6 Blast-safety valves

1.5.7 Lightning protection

2. Automation of the HPA-baking furnace

2.1 General Furnace Automation Requirements

2.2 Controlled parameters

2.3 Safety Automation

2.4 Selection of sensors, instruments and automation equipment

2.5 Functional Diagram Description

3. Technology of organization of construction and installation works

3.1 Work Execution Project

3.1.1 Initial data and brief design characteristics

object

3.1.2 Definition of CIW volumes

3.1.3 Selection and justification of work methods

3.1.4 Work Schedule

3.1.5 Schedule of construction and installation machines

3.1.6 Define requirements for materials, structures and

details

3.1.7 Schedule of materials, structures and

details

3.1.8 Water supply and energy saving of construction

3.1.9 Need for warehouses, temporary buildings and structures

3.2 Flow sheet for gas pipeline laying through the ravine

3.3 Zamerno-zagotovitelnaya the card on a HPA-furnace binding

4. Occupational safety

5. Civil defense

List of literature

Introduction

The development of the gas industry and gas supply to cities, towns and industrial enterprises based on natural gas in Russia began in the mid-40s. The scale and pace of development of the gas industry and gas supply determines gas production. A significant increase in gas production will significantly change the country's fuel balance. While in 1950 gas fuel accounted for only 2.3 per cent of the total fuel balance, in 1983 it was 27 per cent, and in 1990 gas accounted for 33 per cent of all fuels consumed.

In the main areas of economic and social development of Russia for the period until 2000, it was planned to increase gas production to 835850 billion cubic meters, to accelerate the development of the industry.

Further expansion of gasification of cities is planned. Currently, more than 70% of cities are gasified in Russia. By 2001, it was planned to complete gasification of all cities in the country.

Improvement, intensification and automation of technological processes lead to the need to improve the quality of consumable heat carriers. Natural gas meets these requirements most than other fuels.

The rational use of gaseous fuel with the greatest realization of its technological advantages makes it possible to obtain a significant economic effect, which is associated with an increase in the efficiency of the units and a decrease in fuel consumption, easier regulation of temperature fields and the composition of the gas medium in the working space of furnaces and plants, as a result of which it is possible to significantly increase the intensity of production and quality of the obtained products. The use of gas for industrial installations improves working conditions and increases its productivity. The use of gas in industry makes it possible to carry out fundamentally new progressive and cost-effective technological processes. In addition, the use of gas as fuel makes it possible to implement and significantly improve the living conditions of the population, improve the sanitary and hygienic level of production and improve the air pool in cities and industrial centers.

1 Process Part

1.1 Selection of gas supply system

For gas supply to cities, single-stage, two, three and multi-stage gas supply systems are used.

The choice of the number of pressure stages is made from the following: the higher the gas pressure in the gas pipeline, the smaller its diameter and cost, but the laying of the network becomes more difficult, since it is necessary to withstand large breaks to buildings and structures, not all streets can be laid high pressure network. As the number of pressure stages in the system increases, the number of FRG increases, but the diameters of the gas pipelines of the next pressure stages decrease.

For medium-sized cities, a two-stage looped gas supply system is the most expedient. In this system, gas is supplied to GRP, bakeries, laundry, industrial enterprises through a looped high-pressure gas pipeline of the 2nd category. The remaining household and utility consumers receive gas from low-pressure networks.

In the design, hydraulic calculation of low and high pressure networks is carried out. The main task of hydraulic calculation of networks is to select such diameters of gas pipelines that would ensure the passage of the calculated amount of gas, and at the same time, the complete pressure losses on the path from the FRG to the end of the flow in any direction from the FRG would be equal to the single pressure drop accepted for the whole network.

Gas supply of the city district is presented in the calculation.

1.2 Selection of type and quantity of FRG

When designing the gas supply of the city, the correct choice of the number of GRP, their productivity and location is of great importance.

We accept 3 GRP with a load of 1745 m3/h each. EMG shall be located in the center of the area of its operation and as close as possible to the center of the load of the area.

If these centers do not coincide, the GRP must be placed to the center of increased load. When selecting a location for GRP, it is necessary to comply with all SNIP standards and safety rules of Gostekhnadzor for placement and permissible distances to buildings, structures, roads.

EMG are performed according to standard projects developed by Mosgazproekt. FRG are designed for inlet pressure of 3.6 and 12atm. The FRG capacity is selected by the capacity of the pressure regulator.

Based on the selected gas supply system, the required number of lines, outlet pressure and the need to measure gas flow is established.

After that, the diameter of the pressure regulator of RDC2 type and its nozzle are selected according to the required capacity of each thread and the located pressure drop, and the diameters of the FRG, typical drawings are selected from them and the FRG is tied to the area. Wells with shut-off valves are installed at gas inlets and outlets from FRG.

1.2.1 Gas equipment of FRG

To reduce the gas pressure to low, it is planned to build GRP, which are adopted according to the standard project 905011 "Gas control stations separate for gas pressure reduction."

The following equipment is installed in the FRG on the way:

1) filter

2) safety - shut-off valve (BSV)

3) pressure regulator with control regulator

4) safety - relief valve

Cleaning of gas from mechanical particles is performed in the filter installed before the safety valve. We accept the filter Dy 150mm.

Pressure regulators are designed to automatically reduce pressure and keep it constant after itself at a given level regardless of flow rate and fluctuations in inlet pressure. Select RDUK2100 pressure regulator. KN-2 control regulator is used as the control element of pressure regulator.

Shut-off valve is installed upstream of pressure regulator along gas flow and adjusted for maximum permissible increase of gas pressure downstream regulator. The shut-off valve is equipped with RVC and is supported by the diameter of the conditional passage of the regulator. Select safety valve PKN100.

The relief valve is designed to prevent the release of the shut-off valve with a slight increase in pressure downstream the regulator. We select the waste PSK50 valve.

Lighting of the FRG building is natural (through windows) and artificial (electric in explosion-proof design). The building is heated from the local heating plant. The room temperature is maintained at least 5 ° C and controlled by a room thermometer. Ventilation is natural, provides three times air exchange per hour.

1.3 Protection of gas pipeline against corrosion

Depending on gas composition, pipeline material, laying conditions and physical and mechanical properties of soil, gas pipelines are subject to some degree of internal and external corrosion. Corrosion of internal pipe surfaces mainly depends on gas properties. It is due to an increased content of oxygen, moisture, hydrogen sulfide and other aggressive compounds. The control of internal corrosion is reduced to the removal of aggressive compounds from the gas, that is, it is well cleaned. It is much more difficult to control corrosion of the outer surfaces of the pipes laid in the ground, i.e. soil corrosion. Soil corrosion is inherently divided into chemical, electrochemical and electrical.

Chemical corrosion arises from the action on the metal of various gases and liquid non-electrolytes. When the metal is exposed to chemical compounds, a film consisting of corrosion products is formed on its surface. If the resulting film does not dissolve, has sufficient density and elasticity, and is also well blinded to the metal, corrosion will slow down and can cease at a certain thickness. Chemical corrosion is a continuous corrosion in which the wall thickness of the pipe is reduced uniformly. Such a process is less dangerous in terms of end-to-end pipe damage.

Corrosion of metal in soil has mainly electrochemical nature. Electrochemical corrosion is the result of the interaction of a metal that acts as electrodes with aggressive soil solutions that act as an electrolyte.

Electrochemical corrosion has the nature of local corrosion, that is, when local ulcers of great depth occur on the gas pipeline, which, developing, turn into through holes in the walls of the pipe. Electrochemical corrosion also occurs when the gas pipeline is exposed to an electric current that is retained in the ground. Currents fall into the soil as a result of leaks from the rails of electrified transport.

Existing methods of protecting gas pipelines from corrosion can be divided into two groups: passive and active. Passive protection methods consist in isolation of the gas pipeline. Insulation materials used for protection are subject to a number of requirements: monolithic coating, waterproofness, good adhesion to metal, chemical resistance in soils, high mechanical strength, and the presence of dielectric properties.

The most common insulating materials are bitumen mineral and bitumen rubber mastics.

Active methods include cathodic and tread protection and tread protection and electrical drainage. The electric drainage consists in the removal of currents from the gas pipeline, back to the source. Discharge is performed through insulated conductor connecting gas pipeline with rails of electrified transport. When current is diverted from the gas pipeline, the output of metal ions to the soil is stopped and thereby the electrical corrosion of the gas pipeline is stopped. Polarized electric raining is used for current removal. It has one-way conductivity from the gas pipeline to the rails. Cathodic protection is used to protect the gas pipeline from soil corrosion. During cathodic protection, a negative potential is applied to the gas pipeline, i.e., the entire protected section of the gas pipeline is transferred to the cathode zone. As anodes, low-solubility materials are used, as well as waste of black metal, which are placed in the soil near the gas pipeline. Negative pole of DC source is connected to gas pipeline, and positive pole is connected to anode. The electric current exits the anode in the form of positive metal ions, therefore, due to the dissolution of the metal, the anode gradually breaks down.

During tread protection, section of gas pipeline is converted into cathode without foreign current source, and metal rod is used as anode, which is placed in soil next to gas pipeline.

During electrical protection of gas pipelines, insulating flange connections should be provided at the inlet and outlet of the gas pipeline to the ground through metal structures and utility networks, and the gas pipeline should be introduced to the object, which is the source of wandering currents.

1.4 Maintenance and repair of gas pipelines

The task of maintenance and preventive repair is to maintain the gas pipelines and structures on them in a state that ensures safe operation and uninterrupted supply of gas to consumers. As a result of damage to gas pipelines (breaking of joints, through corrosion of the walls of pipes, fittings and equipment), an explosive concentration can form.

Systematic monitoring of the state of gas pipelines, their equipment and valves is established in order to timely clarify the places of leakage.

Gas pipeline routes are regularly inspected. External inspection of the route checks the gas content of wells and control tubes. During inspection, the state of the valves is checked and minor repairs of the gas pipeline equipment are carried out.

To monitor the state of underground gas pipelines, an instrument method of their examination is used, which is carried out at least 5 years. It includes checking the state of the insulation coating of the gas pipeline and checking the tightness. Quality control of insulation is performed by ANPI insulation damage detection apparatus. Using the ANPI apparatus, the conditions of the insulation coating are checked without opening the soil and pavement. When monitoring the tightness of the gas pipeline with instruments of the "Universal" type, soil above the gas pipeline, gas wells, control tubes, as well as wells of other underground utilities located up to 15 meters from the gas pipeline are checked for gas contamination.

Preventive repair of gas pipelines includes monitoring of the state of the gas pipeline, insulation, valves and equipment, their maintenance and ongoing repair. On the basis of preventive inspection and repair, a conclusion is made about the suitability of the gas pipeline for long-term operation. If the state of the gas pipeline is unsatisfactory (severe corrosion, disorder of a large number of connections, clogging of pipes, etc.), the gas pipeline is overhauled.

1.5 Bakery gas supply

1.5.1 Characteristics of the object

The bakery is located in the city of Orenburg. In the oven shop two furnaces tipaFTL2 and two HPA40 furnaces intended for production of bakery products and also the built-in boiler house with four coppers of E-1-9G are installed. The room of the boiler house according to explosive explosion and fire safety belongs to category B and D and has a fire resistance degree of II. Two evacuation exits located dispersed are made from the bakery hall and the boiler house. The noise characteristics of the bakery do not exceed sanitary standards (80 Db).

The supply of natural gas to boilers and furnaces is provided from the external high pressure gas pipeline through the FRG, where the gas pressure is reduced to the required pressure before the burners (taking into account pressure losses in the supply gas pipelines).

Gas pressure at inlet to FRG is 0.36 MPa; gas pressure upstream of burners of boilers and furnaces 0.08 MPa.

1.5.2 Main Design Solutions for Gas Supply

In this project, internal gas equipment of the furnace compartment and boiler house is being developed.

Inlet of D100mm gas pipeline is performed at elevation 0.9m.

Short characteristic of FTL-2 type furnace:

1. Working area of hearth 16m2

2. Temperature in the furnace chamber 180220 ° С

3. Flue gas temperature at furnace outlet 250350 ° С

4. Discharge at the outlet of the furnace 10 dPa.

Short characteristic of the HPA-40 furnace:

1. Working area of the hearth 38m2

2. Temperature in the furnace chamber 180220 ° С

3. Flue gas temperature at furnace outlet 250350 ° С

4. Discharge at the outlet of the furnace 10 dPa.

All equipment and gas pipelines are selected taking into account the installed capacity of the units in full accordance with [2].

Baking FTL2 and HPA40 furnaces are equipped with block injection BGI12 torches on two on each furnace - one rastopochny, one worker.

Short characteristic of BIG-1-2 burner:

1. Torch nominal thermal power 308 kW

2.Nominal gas flow rate 46 nm3/h

3.Nominal gas pressure upstream of burner 0.08 MPa

4. Burner operating control factor 3,8

5. Excess air ratio at the burner outlet 1.05

The internal gas pipeline (header) is made of Du80 pipes and passes at a height of 2.7 m from the floor level.

In the course of gas movement, the following are installed at the depressions to the furnaces:

gate valve dy50,

purge gas line and igniter gas line,

two MPS solenoid valves, safety gas pipeline between them and working valve dy20,

adjustment flap of ZD15 type,

working valve dy20 for each decay burner.

The purge gas pipeline and the safety gas pipeline are 1 meter above the roof of the building and are grounded.

To account for gas flow to bakery ovens, the design provides for the installation of a gas meter of the type SG16200 dy80. Certificate capacity of the counter at pressure of 2.3 kgf/cm2 is:

maximum flow rate 200 nm3/h;

minimum flow of 40 nm3/h.

Summary of boiler E-1-G:

1. Thermal performance at Qn = 7960 kcal/nm 0.56 Gcal/h

2. Steam pressure is not more than 0.9 kgf/cm2

3.Computed fuel flow rate 86.5 nm3/h

Boilers are equipped with block injection burners of the BIHm type. A distinctive feature of these burners is the presence of separate mixers. Axes of nozzles are directed at some angle to axis of mixer. Due to this arrangement of the nozzles, as well as the choice of the diameter of the mixer at the outlet, a velocity profile is created that prevents the flame from slipping. Fire separation is prevented by refractory brick tunnel.

The advantage of this type of burner is the high completeness of fuel combustion at low air excess factors, small overall dimensions, low noise level. Installation of BIHm burners improves the safe operation of the boiler, reduces the number of instruments. Boilers equipped with BIHm burners have higher efficiency.

Brief characteristics of BIGM-2-4 burner:

1. Nominal heating capacity 0.73 Gcal/h

2.Nominal gas flow rate 92 nm3/h

3.Nominal gas pressure upstream of burner 0.08 MPa

4. Burner operating control factor is not less than 3.

For the commercial gas flow metering unit, the project provides a gas meter of type SG16m400. The meter is equipped with gas pressure and temperature recording devices.

Gas meters of the type SG16200, dy80 with installation of gas pressure indicators are provided to account for gas flow to the boiler room and furnace shop.

Gasket of gas pipelines is accepted open along supports and on brackets. All gas pipelines are equipped with blowdown and safety pipelines. Blowdown and safety pipelines are removed above the coating cornice by at least 1.0 meters.