Diploma project on the topic: "Gas supply of a residential area"
- Added: 14.04.2018
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Description
The purpose of this work is to develop a gas supply system for a residential area with the connection of a roof boiler room for a 25-story apartment building. Sheet 1. The residential area under consideration is represented on this general plan. The gas of the Urengoy gas field is supplied through the 2nd connection points to medium-pressure gas consumers (GRP and SHGRP, laundry, bakeries, baths) with a pressure of 0.33MPa at the tie-in point. The gasified area includes 5 and 9 buildings. Gas supply to consumers is carried out through steel underground gas pipelines connected to each other by welding. For their protection against electrochemical corrosion, passive protection is provided in the form of enhanced insulation of gas pipelines, and the active of 5 cathode stations with a range of 426 m. Gas wells are also represented, gate valves and two-lens compensators are installed in them. Sheet 2. In accordance with the regulatory documentation, loads are determined and gas costs are calculated. To improve the reliability of the gas supply system, ring circuits for medium and low pressure networks were adopted. Hydraulic calculation of medium pressure is performed in 3 modes (in normal and in 2 emergency conditions under condition of failure of one of gas supply sources). In emergency mode, the situation is considered when the gas supply to consumers in the emergency half-ring is reduced to 70% of the design one, except for bakeries, and the boiler room is switched to reserve fuel. Sheet 3. For the gas supply needs of residential 5-storey buildings, in the kitchens of which there is a 4-block gas stove and a high-speed water heater for the needs of the GVA. Hydraulic calculations were made for intra-house and intra-quarter networks. External intra-quarter network laying with branches on building facades. Sheet 4. Based on the adopted design decisions, the project for the construction of a gas supply system was completed. The PWP consists of the work execution network, the production diagrams of the main types of construction and construction plans. An in-line method of performing work was adopted with the breakdown of the route into 6 grips performed by specialized teams with the maximum combination of works that ensure construction on time. The estimated construction cost for 12.6 km of the route amounted to 50.4 million rubles. Sheet 5. ShGRP is powered from a steel underground gas pipeline with a diameter of 219x6.0 mm with a tie-in pressure of 0.29 MPa. A vertical outer steel gas pipeline crashes into it, which rises to an elevation of 2.2 m above ground level and is made of an electric welded pipe with a diameter of 57x3.5 mm. At the outlet of the gas pipeline from the ground at a distance of 0.5 m from the ground level, an insulating connection is provided. At a distance of 1.8 m from the ground level, a disconnecting device with a diameter of a conditional passage of 50 mm with a nominal pressure of 1.6 MPa is installed. The horizontal section is supported by vertical posts, the bases of which are concreted under ground level. The cabinet is made of non-combustible steel, painted with fire-retardant yellow paint over the entire external surface, red FIRE HAZARDOUS GAS inscription is applied on the cabinet door. The functional diagram consists of 2 identical gas flow lines (main and standby), on its path there are: disconnecting devices for stopping gas supply in cases of repair or emergency situations; a gas filter removing mechanical impurities from the natural gas composition; pressure regulator reducing gas pressure from 0.29MPa to 3.5kPa. The cabinet is heated by a gas heater, in front of which a pressure regulator is installed. Candle heads are brought outside to a height of 4 m from ground level. To prevent unauthorized penetration, the ShGRP has a fence along the entire perimeter, made of a 1.6 m high wire mesh attached to vertical posts, the bases of which are concreted. The zone of protection against lightning in the ShGRP has a radius of 4.1 m. Sheet 6.The above-ground laying of the gas pipeline after leaving the ShGRP and to the roof boiler house is made of steel pipes with an external diameter of 159x4.5 GOST 10704-91. After the gas pipeline is withdrawn from the SHGRP, it is provided to install a KShTF disconnecting device with a diameter of a conditional passage of 150 mm at elev. + 2.5 m from the ground level. The introduction of the gas pipeline into the boiler room is provided at elev. + 78.400 m in a steel case with a diameter of 273x5 mm. For the heating needs of a residential apartment building, the boiler house provides for the installation of 3 floor boilers of VIESSMANN type VITOPLEX 200 SX2 with a capacity of 900 kW each, with a total capacity of 2700 kW. The distance between the boilers is not less than 1.1 m, sufficient for maintenance. The glazing of the boiler house serves for natural lighting and as easy-to-throw structures. The glazing area is accepted in the amount of 3% of the volume of the boiler room, but not less than 0.8 m2 of one glass with a thickness of 3 mm. The glazing area of the boiler house is 76.3 m2. To prevent emergency situations, a fast-acting electromagnetic gas shutoff valve is provided at the gas pipeline inlet to the boiler room, stopping the gas supply to the burners in case of unacceptable gas pressure drops, as well as in case of gas pollution of the boiler room with natural or carbon monoxide gas. Control of gas content level in the boiler house by natural and carbon monoxide gas is performed by stationary single-channel gas content indicators EVRM-NC. Blowdown pipelines with gas sampling nozzles are also provided. The gasket of the gas pipeline in the boiler room is provided on brackets attached to the wall and on ceiling mounts at an elevation of + 2.2 m from the boiler room floor, sufficient for people to pass. On the branches of gas pipelines to the boilers, the installation of disconnecting devices is provided - KShTsF Du100 at el. + 1.1 from the boiler room floor level. The boilers are equipped with forced air burners of type WM-G20/2-A ZM-LN from Weishaupt. Accounting of gas flow in the boiler room is provided by the SG-EC measuring complex based on the RVG 250 meter manufactured by Elster Gazelectronics, installed at an elevation of + 1.6 m from the boiler room floor level. MADAS gas filter is installed in front of measuring complex. Blowdown plugs from the internal gas pipeline are brought one meter above the boiler room roof skate. Ventilation of the boiler room is made from the condition of providing 3-fold air exchange per hour plus air for combustion. Plenum ventilation of the boiler house is natural, through fixed louver grilles of the AMR type, installed in the upper part of the outer wall. The boiler room exhaust ventilation is natural, it is carried out through 2 Du 630 mm deflectors installed on the boiler room roof. Exhaust of combustion products from boilers is provided through steel chimneys with outer diameter of 325x6.0 mm, located outside the boiler house, the mouth of which is located at a distance of + 84.200 m.
Project's Content
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Пояснительная записка.docx
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Диплом.dwg
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Additional information
Contents
Introduction
1. GAS SUPPLY
1.1 Initial data
1.2 Calculation of main gas characteristics by gas composition
1.3 Calculation of population and hourly gas consumption per quarter
1.4 Determination of annual gas consumption by domestic and small utility consumers
1.4.1 Calculation of gas hourly flow rates by development zones
1.4.2 Determination of specific gas hourly flow rate per person
1.4.3 Low Pressure Ring Routing
1.4.4 Determination of specific gas travel expenses in sections of street distribution network
1.4.5 Determination of estimated gas hourly consumption by street distribution network sections
1.5 Hydraulic calculation of low pressure street distribution network
1.5.1 Hydraulic calculation of internal gas pipeline
1.5.2 Hydraulic calculation of intra-quarter gas pipeline
1.6 Calculation of medium pressure gas consumption by utility facilities
1.6.1 Operation modes of the gas network
1.6.2 Hydraulic calculation of medium pressure street distribution network
1.7 Calculation of equipment selection for GRP
1.7.1 Calculation of pressure regulator selection
1.7.2 Selection of safety-shut-off valve
1.7.3 Selection of safety relief valve (UCS)
1.7.4 Gas filter selection
1.7.5 Gas Meter Selection
1.8 Calculation of the number of cathode stations
1.9 Protection of FRS and FRS against lightning
1.9.1 Calculation of EMG lightning protection radius
Conclusions
2. CIW Technology and Organization
2.1 Data for calculation of work organization
2.2 Determination of Scope of Work
2.3 Compiling the Labor and Wage Cost Sheet
2.4 Selection of construction machines and mechanisms
2.5 Determination of freight volume and number of vehicles
Conclusions
3. BOILER ROOM GAS SUPPLY
3.1 Heat engineering calculation and selection of number of boilers
3.2 Calculation of fuel consumption
3.3 Hydraulic calculation of LP external gas pipeline
3.4 Selection of pressure regulator on PGRS
3.4.1 PRGSH lightning protection
3.5 Automation of boiler room gas supply
3.6 Gas Flow Metering
3.7 Ventilation of the roof boiler house
3.8 Exhaust of combustion products
Conclusions
CONCLUSIONS AND RECOMMENDATIONS
LIST OF SOURCES USED
Introduction
Modern urban distribution systems are a complex complex of structures. Each of them includes the following elements: low, medium and high pressure gas networks, gas control stations (GRS), gas control stations (GRS) and gas control plants (GRU). In these plants, the gas pressure is reduced to the required value and the subsequent automatic maintenance of the pressure value at a constant level.
The design of the gas supply system is based on the plans, diagrams and master plans of settlements and ultimately must meet certain requirements, such as: uninterrupted gas supply to consumers, simplicity and convenience of maintenance, safety of operation, the possibility of disconnecting individual elements of the system or sections of gas pipelines.
The main element of the gas supply - the gas pipeline - is classified by gas pressure, configuration, purpose. Depending on the tasks and conditions, the gas supply scheme can be circular, dead end or combined.
Low-pressure gas pipelines supply gas to residential, public buildings and small utility consumers. Large household (baths, laundries and boiler houses) and production consumers (GRP, the industrial enterprises (plants, factories, etc.)) and regional boiler houses are supplied from networks of an average or high pressure. Communication between gas pipelines of different pressures is carried out only through FRG or cabinet FRG (FRG).
Due to higher reliability, street distribution networks have a ring configuration, and intra-quarter and intra-house ones have a dead end, but for gas networks both, underground laying is preferable. Laying of on-site networks of industrial enterprises is allowed above ground. It is recommended to carry out the distribution gas pipeline of the internal house network along the perimeter of the building.
Low Pressure Ring Routing
The routes of street gas pipelines are designed from the condition of shortest distance, that is, from the condition of minimum length.
Guided by the principle of reliability of gas supply, the low-pressure network is designed as a ring, consisting of several rings (circuits) and one or three FRG.
The drawn up scheme is considered correct if it provides for the ability to connect (power) all neighborhoods of the district to the gas pipeline on one side. As an exception, you can connect a small quarter through another quarter. The main transport passage in the area should be determined (assigned), since the main transport highways, main passages and avenues, as well as places of large crowds of people are areas that are undesirable for laying a gas pipeline.
After the routing, the resulting rings shall be numbered, GRP shall be placed and gas flow meeting points shall be assigned on the basis that the most optimal range of the GRP is 600800 m and the range of the gas pipeline (the distance from the FRG to the meeting points) is 8501050 m, respectively. It should be borne in mind that in the future hydraulic calculation of the street distribution network it will be necessary to link the hydraulic resistances of the "parallel" sections of the network (two or more branches consisting of one or more sections having a common starting point and receiving gas from the same section) with an accuracy of ± 10%.
Parallel sections can be located both on outer contours of rings and on inner ones. At the same time, the sections on the external circuits carry the load of only one ring, and the internal ones carry the load of the two rings, between which they are located, so they are more loaded. On this basis, the length of the sections on the inner contours should be taken about 1.52 times less than the length of the branches (sections) located on the outer contours.
After the meeting points of gas flows in all directions of movement from all EMG are numbered, the network should be divided into calculated sections. Each point of branching or merging of gas flows at intersections of the street network, connection of neighborhoods, GRP, etc., are numbered. The calculated run is the distance between any two adjacent points. The numbering order can be any, since it does not affect the results of the calculation.
The calculated scheme is drawn at a scale of 1:5000 with the designation of the calculated areas, the length of which is determined by the scale.
Conclusions
In the gas supply section, calculations were made to determine gas consumption for the needs of the Smolensk region. The total consumption of gaseous fuel was 19649 m3/h. They also calculated the selection of optimal diameters of the steel gas pipeline, and calculated the selection of GRP equipment, which provides stable and reliable operation of the gas network.
Boiler house gas supply
One of the more used options for autonomous heat supply is a roof boiler room. As a rule, it operates on natural gas and is fully automated. It is envisaged to connect (process connection) to the gas distribution network of a 25-storey residential building with built-in non-residential premises. The boiler house is located at elev. + 76.200 in axes 811, D-I and fully complies with the requirements of environmental, sanitary, hygiene, fire and other standards applicable in the territory of the Russian Federation and ensures safe operation of the facility for life and health of people, provided that the measures stipulated by the working drawings are observed.
3.5 Automation of boiler room gas supply
According to the parameters of the boiler, all automation, including safety and regulation, is provided in the set of the boiler itself and ensures the cessation of gas supply to the burners when the power supply is turned off, the gas pressure is increased or decreased, the thrust in the gas duct downstream the boiler is reduced, the gas flow rate to the main burner is stabilized when the gas pressure at the inlet changes.
The installation of the "STG11D20 (c)" type gas detector is considered, which provides light and sound signals at a gas concentration of 10% of the lower concentration limit of flammability of natural gas (methane - CH4) and an excess of + 25 mg/m3 of carbon monoxide content in the boiler room with its connection to the isolation solenoid valve EVRMNC of Elektrogas, installed at.
The design provides for the possibility of measuring the gas pressure in front of the burner, as well as a connector for connecting devices for monitoring thermal analysis, composition and temperature of combustion products .
The sensor of a gas-signaling device "STG11D20 (v)" is installed in potentially possible place of leak of gas, at distance of 0,20,3 m from a ceiling. The carbon monoxide sensor is installed near the entrance door at a height of 1.51.8 m from the floor, but no closer than 2 meters from the supply air.
The boiler automation units maintain the set water temperature at the boiler outlet. Operating boiler room equipment requires constant supervision by maintenance personnel. The signal "Emergency" is output to the control panel located in the security room.
3.6 Gas Flow Metering
For accounting of a consumption of gaseous fuel measuring SGEKR0.2400/1.6 complex on the basis of RVG 250, expansion 1:50 is picked up. Gmin = 20 m3/h, Gmax = 390 m3/h, P = 2500Pa. The unit-by-unit gas metering is also provided using gas turbine meters STG100250 installed in front of the gas frame of each of the burners .
3.7 Ventilation of the roof boiler house
Supply and exhaust ventilation with natural exhaust and inflow. The volume of the minimum air exchange is three times the exchange taking into account the air removed by the blast fans on the burners. Gas combustion air is supplied from outside through plenum grate with preliminary heating by means of water fan. Three-fold air exchange in the boiler room is carried out through the plenum grid 600x550 mm above the boiler room door opening and 2 exhaust air ducts Du630 in the boiler room roof with 2 Du630 deflectors of the 5.90451 series.
3.8 Exhaust of combustion products
Combustion products are removed from boilers through three separate chimneys with internal diameter D300 mm. The mouth of the chimneys is located at elev. + 84.200. The chimneys are provided with connectors for sampling combustion products, their temperature, thrust in the gas duct, as well as blast valves Du300 equipped with branch ducts to ensure the safety of maintenance personnel. The gas duct is laid with a slope towards the boiler. Maximum temperature of exhaust flue gases from boilers shall not exceed 195 ° С. Chimneys are metal, insulated, have a protective coating of galvanized steel.
Conclusions
In the gas supply section of the boiler house, calculations were made of the required thermal power and gas consumption for the heat supply needs of the roof boiler house. They also selected modern equipment that ensures reliable and safe operation of the boiler room.
Conclusion and recommendations
This final qualification work considers measures for the safety of construction and operation of gas supply systems. As a result of the design of the gas distribution network, gas costs for the quarter and for sections of the street distribution network were determined. Hydraulic calculation of medium and low pressure networks was carried out, based on the results of which the diameters of gas pipelines were selected, equipment for FRG and SGRP was selected, cathode stations were calculated for active protection of gas pipelines from corrosion .
We considered the optimal choice of land transportation machines their number and technical characteristics, installation and testing of the pipeline. They calculated the labor costs and wages for the installation of the designed gas pipeline and determined its estimated cost.
They designed an optimal gas supply system for a roof boiler room, which provides costs for heating and hot water supply systems for a 25-story residential apartment building. This boiler house is fully automated and operates without the presence of working personnel.
The gas supply system of the Smolensk region according to the task was designed from steel electric welded pipes. The project has been completed in accordance with the requirements of the design and safety standards. Currently, in addition to steel underground gas pipelines, polyethylene gas pipelines are widely used. Therefore, the main recommendation can be the use of such pipelines, since the main advantages are a decrease in material consumption, due to a decrease in the diameter of the pipeline and the absence of lens compensators, and corrosion protection is not required.
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