Heat supply of the district of Astrakhan

Contents

Contents

Source Data

Heat supply system description

Definition of design heat loads

Plot Temperature

Plot annual heat consumption

Determination of design coolant flow rates

Hydraulic calculation of heat networks

Piezometric Plot

Selection of pumps

9.1 Selection of network pumps

9.2 Selection of makeup pumps

List of used literature

1 Initial data

2 - plan of the district of the city [1, prilozh. A]

2 - warmth source location [1, prilozh. B]

The project provides for a two-pipe water heat supply system, the source of heat is a CHP.

Development district - Astrakhan

Heat supply system - closed

Design temperature parameters of coolant according to heating schedule - 14070 ° С

Outside air design temperature:

- for design of heating of tn. about = -21 °C

- for design of ventilation tn = -10 ° С

- average temperature of external air for the heating period of tcp. about =-0.8 °C

- wind speed in January 3.8 m/s

- heating period duration no = 164 days

- absolute temperature tabs = -33 ° С

Heat supply system description

The heat supply system consists of the following components :

thermal energy source;

heat network;

heat consumers.

In this course project, a closed two-pipe heat supply system was designed. The main sources of district heat supply are industrial and communal heat stations for combined heat and electric energy production - CHPs built near industrial centers and cities. The predominant number of thermal power plants has thermal networks with an average range of 1015 km. The construction of the CHP far beyond the city is explained by the high requirements of sanitary standards for the cleanliness of cities and the air basin, as well as the economic benefits of approaching thermal plants to local fuel bases and water sources.

In the heat supply system as network circulation pumps.

The project has developed main heat networks made of strong steel pipes, the laying of which can be above ground or underground.

Above-ground laying is used on the territory of industrial enterprises, on sites free from development, outside the city or in a place where heat networks do not affect the architectural decision of the city and do not interfere with traffic .

Underground laying is provided in cities and rural settlements, since it does not interfere with traffic, does not affect the architecture of the city, reduces pipeline losses due to the use of heat-insulating soil properties. The freezing of soils is not dangerous for thermal conductors, so they can be laid in the zone of seasonal freezing of soils, i.e. 0.5 the 2m from the ground surface. The pipeline is always laid above the groundwater level. If this is not possible for any reason, associated drainage and enhanced smeared bitumen insulation should be provided .

Underground gasket can be channel and channel-free.

Pipelines are laid on fixed supports, using shield and frontal supports.

Frontal supports are mainly used in chambers, passage and semi-passage channels. Thrust structure is made of channels of different sizes. Embedded in the bottoms and floors of structures.

Panel supports are used for fixed clamping of pipes in chambers, impassable channels and for channel-free gasket. Axial load of pipelines is transmitted to vertical planes of soils through panel supports during channel-less laying.

The heat conduction slope of the heat networks, regardless of the direction of the coolant movement and the method of laying the heat networks, should be not < 0.002 m.

According to the water supply method, the heat supply systems may be open or closed.

Closed - water for hot water supply is taken from the water supply and heated in the heat exchanger with network water.

Open - water for hot water supply is taken directly from the thermal network. Corrosion and scale in heating plants and heat networks.

Thermal insulation of pipelines and equipment of heat networks is used in all laying methods regardless of coolant temperature. Materials used as heat insulators shall have thermal protective properties and low water absorption over a long service life. Such heat insulating material may be reinforced concrete, bitumoperlite or bitumoceramsite. Thermal insulation operations are performed in a certain process sequence.

In district heating systems, heat is spent on heating the building, heating the flowing air in ventilation and air conditioning plants, hot water supply, as well as technological processes of industrial enterprises.

Heat loads on heating and ventilation are seasonal, as they depend on the temperature of the outside air and other climatic conditions of heat supply in the city area. If the outside air temperature is equal to or higher than the normalized air temperature in the heated room, then heat energy for heating and ventilation is not required.

The heat load on the hot water supply and on the technological processes of the enterprise industry is year-round, since thermal energy is consumed during the year and depends little on the temperature of the outside air.

АдилгалиевТГВ17-1ЦТС.dwg