Kursovoy - Gas supply of the city district

Contents

CONTENTS

p

1 Source Data Selection

2 Calculation of gas consumption

3 Determination of annual gas expenditures by consumer categories

3.1 Annual gas consumption by residential buildings

3.2 Annual gas consumption by public utilities

service

3.3 Annual gas consumption at catering facilities

3.4 Annual gas consumption by health care institutions

3.5 Annual gas consumption at production facilities

bakery and confectionery products

3.6 Annual gas consumption for heating and ventilation of residential and

public buildings

3.7 Annual gas consumption by motor vehicles

4 Determination of estimated hourly expenses

4.1 Determination of estimated hourly gas consumption for residential buildings and

unaccounted for consumers

4.2 Determination of the estimated hourly flow rate of gas for heating and

ventilation of residential and public buildings

4.3 Determination of estimated hourly flow rate of gas by motor vehicles

5 Determination of specific gas flow rate

6 Determination of optimal radius, load and quantity

gas control stations

7 Calculation of medium (high) pressure gas pipelines

8 Calculation of low pressure gas pipelines

9 Calculation of intra-quarter and intra-house gas pipeline network

10 Literature

Ministry of Education and Science of Ukraine

Odessa State Academy of Construction and Architecture

Institute of Engineering and Environmental Systems

Department of Heat and Gas Supply

EXCHANGE RATE PROJECT

On the topic: "Gas supply of the region of the city of Yevpatoria"

.

Calculation of gas consumption

The population is set according to statistical data taking into account population growth by the end of the design period. The gas supply coverage and the estimated period are established in the task on the basis of the plan for the prospective development of the city district and are issued by the local administration. In the absence of such data, it is recommended to determine the number of inhabitants by the standard population density per unit of settlement territory.

The number of inhabitants in the quarter is determined by dependence:

N = fkv • a, people

Where:

N-number of inhabitants in the quarter, people;

fq.- area of the quarter, ha;

a - density of people/m2.ia, people/m2.

Determination of annual gas expenditures by consumer categories

Annual gas consumption is the basis for drawing up a gas supply project for the city district.

Gas consumption is calculated based on the design task depending on the percentage of coverage for household and municipal needs, according to the heat consumption standards for various consumers, MJ/year, and the combustion heat of the received gas, kJ/year, taking into account the efficiency of the plant.

The main reference material for performance of design works is DBN V. 2.5 [1].

Based on the given data, gas consumption is calculated by categories of consumers.

3.1 Annual gas consumption by residential buildings.

3.1.1 Gas consumption for cooking on the gas stove at home:

3.2 Annual gas consumption by public utilities

maintenance.

3.2.1 Mechanized laundry, including drying and ironing of laundry:

3.2.3 Non-mechanized laundry rooms with drying cabinets:

Qf = 50 MJ/( year • t), Qd = 40 MJ/( year • t) - heat flow rate for 1wash in bath or shower [1];

η=0.65 - the efficiency of gas-using installations;

3.3 Annual gas consumption at catering facilities.

Gas consumption for cooking in public canteens:

3.4 Annual gas consumption by health care institutions.

3.4.1 Hospitals:

cooking and hot water [1].

3.5 Annual gas consumption at production facilities

bakery and confectionery products.

Gas consumption for bakery and confectionery products baking:

3.6 Annual gas consumption for heating and ventilation of residential and

public buildings.

3.6.1 Gas consumption for heating of residential and public buildings shall be accepted according to the relevant projects or in accordance with SNiP 2.04.0591 change No. 1 and DBN V. 2.5 [1]:

Where:

K = 0.25 coefficient, taking into account heat consumption for heating and ventilation of public buildings;

tvn=18˚C;tsr.o=2,4˚C;tpo= 16˚C - temperature of internal air of heated buildings, average of external air during heating season, design external air for heating design, [2];

q = 0.503 kJ/( h • m2) - an enlarged indicator of the maximum hourly heat consumption for heating buildings;

Fg - residential area of heated buildings, m2:

3.6.2 Gas consumption for ventilation of public buildings shall be accepted according to the relevant projects or determined in accordance with the instruction [1]:

Where:

Z = 16 - the average number of hours of operation of the ventilation system of public buildings during the day;

K11 = 0.4 is a factor that takes into account the heat consumption for ventilation of public buildings.

3.7 Annual gas consumption by motor vehicles.

The calculation of gas consumption by motor vehicles should be made based on the average daily car mileage of 100 km and the average annual load of 300 days.

We choose the number of cars arbitrarily according to models with a certain liquid fuel consumption per 100 km.

The annual gas consumption by vehicles will be

Determination of estimated hourly expenses

Gas consumption in the village is unstable over time. Fluctuations in gas consumption are observed throughout the year (monthly fluctuations), during the month (weekly or daily fluctuations) and during the day (hourly fluctuations). At the same time, fluctuations in gas flow rate between different consumers do not coincide with each other.

Calculation of diameters of city distribution gas pipelines of various purposes and pressures, as well as calculation and selection of equipment of gas-using plants, gas-regulating points and gas-distributing stations is carried out according to the value of calculated hour gas flow rates, the value of which is determined on the basis of studying gas consumption modes by various categories and types of consumers.

[1] recommends to determine the maximum design hourly flow rate of gas under normal conditions for household and communal needs as a fraction of the annual flow rate depending on the number of inhabitants.

4.1. Determination of estimated hourly gas consumption for residential buildings and

unaccounted for consumers.

The gas supply system is calculated for the maximum hourly flow rate:

4.2. Determination of the estimated hourly flow rate of gas for heating and

ventilation of residential and public buildings.

The mode of gas consumption for heating and ventilation of buildings depends on the climatic conditions where the settlement is located and the method of heating buildings.

Distribution of the annual gas flow rate for heating and ventilation by months is performed by the factor of the monthly gas flow rate for the heating period:

The sum of the products of the design temperature differences per the number of heating days of the respective months of the heating period

4.2.1 Determination of monthly gas heating and ventilation costs:

4.2.2 Determination of daily gas consumption for heating and ventilation :

4.2.3 Estimated hourly flow rate of gas for heating and ventilation, residential and public buildings:

Z = 16 hour/day - the number of hours of operation of the ventilation system of public buildings during the day.

4.3. Determination of the estimated hourly flow rate of gas by motor vehicles.

Calculation of hourly gas consumption by motor vehicles is made according to the data on the number of working hours of cars during the day and the operating mode for the year:

Where:

Determination of specific gas flow rate

All gas consumers, depending on the value of the design hourly flow, are divided into consumers with evenly distributed or concentrated gas extractions in the network.

Facilities with a load of less than 25 m3/h belong to consumers with evenly distributed flow rates and are connected to low-pressure distribution street gas pipelines.

Objects with a load of 2550 m3/h, belong to consumers with a concentrated flow rate and are also connected to low-pressure street gas pipelines.

Specific gas consumption per 1 person:

Determine the optimal radius, load, and quantity

When designing multi-stage gas supply systems, the question arises about the economically optimal range (Ropt) of gas control points. With an increase in the number of GRP, the cost of the low pressure network decreases, but the cost of the GRP itself, as well as medium or high pressure gas pipelines supplying the GRP, increases. Obviously, there is an optimal radius value at which the total annual cost of the system shown is minimal.

low pressure;

Calculation of medium (high) pressure gas pipelines

The task of hydraulic calculation is to select optimal diameters of sections of medium (high) pressure distribution gas pipelines, which provide the design flow rate and the required pressure at consumers.

Hydraulic calculation of medium (high) pressure distribution networks is performed as follows:

1. The selected medium pressure network (dead end) diagram is numbered by the nodal points of gas flow division. We assign the calculated direction of gas movement from the GDC to the most distant consumer. The numbering of the nodes starts from the GPC in the selected calculated direction of the route, then in the same sequence we number the branch sections.

2. We determine the calculated lengths of the sections and the total length of the route according to the accepted design direction:

5. We determine diameters in sections of the network of the design direction. Based on the value of V flow rates in the sections and the average value of SD, we select diameters starting from the GDC to the final consumer according to the nomogram.

6. We calculate the branch. The calculation order is the same as for the main calculation direction. The initial pressure at the branch corresponds to the pressure at the connection point.

Calculation of low pressure gas pipelines

1. Draw on a scale a multi-ring distribution network that repeats the outlines of quarters. Residential and public buildings are connected to the street distribution network through intra-quarter gas pipelines through several inputs. Typically, inputs to neighborhoods are designed after the calculation of the street network, so the flow rate in the network sections is considered evenly distributed, that is, there is an assumption that the same amount of gas, called specific flow rate, is taken from each linear meter of the distribution network.

2. Nodal points at the crossings of gas pipelines are assigned numbers in an arbitrary order. A linear mesh line bounded by two adjacent points is a calculated section.

3. We select the directions of gas flows (directions indicated by arrows) along the shortest distances to distant points of departure. Here we strive for the equality of gas flow distances from the GRP to the endpoints of the network. Network endpoints are called null.

4. We determine the estimated gas consumption in the network sections. The amount of gas taken in the design section "on the way" is called the flow rate.

Its value is determined from the expression:

To determine the diameter of the design section of the gas pipeline, we introduce the concept of equivalent flow rate. This is such a concentrated flow rate that is equal to some part of the track flow rate, and in a given area causes the same losses as the track flow rate.

In multi-ring networks, at an unknown number and points of connection of branches, the flow rate is determined as follows:

The estimated consumption is defined as the sum of the transit and equivalent consumption.

The transit flow rate is the flow rate of subsequent sections passing through a given section without change, for example, for section 813 is defined as follows:

After determining the transit costs in the sections of the microdistrict, we will check the correctness of the calculation, for example:

5. We determine the diameters and head losses in the sections in the following order:

a) the average specific pressure loss at each design direction is determined by the value of the design pressure drop. The calculated directions are semi-rings of large rings from FRG to release points:

b) by nomogram, by value of design expenses and specific head loss, we select diameters of design sections and actual losses on semi-rings.

c) calculate the total head losses in the half-ring sections. The actual value of head losses shall not differ from the available value by more than 5%.

The calculation results are summarized in Table 8.1.

9. Calculation of intra-quarter and intra-house gas pipeline network.

Diameters and head losses of intra-quarter and intra-house networks are calculated according to the same formulas and nomograms as low-pressure street distribution gas pipelines. The calculation order is as follows:

1) The calculated flow rate at the sections of the intra-quarter and intra-house gas pipeline network is determined by the formula:

The nominal gas flow rate, m3/h, is determined by the thermal loads and the lowest combustion heat of the gas used:

Gas pipelines in the quarter are laid on brackets along the walls of buildings above the windows of the first floor. The numbering of the calculated sections on the diagram leads from the connection point to the street gas pipeline towards the farthest point of the quarterly network.

2) Design length of intra-quarter gas pipelines:

Using a nomogram, we determine the diameter and actual value.

Calculation data is summarized in Tables 9.1, 9.2, 9.3.

Literature

1. DBN V. 2.5 Gas supply, K. 2000. M.: TSITP Gosstroy of the USSR, 1988, 64s.

2. SNiP 2.01.82 "Construction climatology and geophysics," M.: Gosstroy of the USSR, 1983g., 136s.

3. Ionin A. A. "Gas Supply" Stroyizdat, 1989

4. Staskevich N.L. and others. "Handbook on Gas Supply and Use" L. Nedra, 1990

5. Methodological guidelines for the course project "Calculation of gas consumption of settlements." Odessa OGASA 1988, 29s. Orobets V.V., Skrebnev A.F., Kochkin M.M.

6. Methodological guidelines for the course project "Gas supply of the city district." 1985, 78 pages. Skrebnev A.F.